There has been some discussion recently about whether there should be a CSS4, as in a defined “next version” of CSS. In this article, I take a look at the discussions around this, the pros and cons of creating a feature release for CSS, and the potential problems in deciding what goes into it. I’m using the term CSS4 as that is how the discussion was started, and not attempting to discuss what the naming should actually be, should this approach be taken forward.

https://www.smashingmagazine.com/2020/03/css4-pros-cons-discussion/